This invention relates to an apparatus for preventing the overfilling of a vessel with fluid and in particular but not exclusively to an apparatus for preventing the overfilling of a bathtub with water.
It is well known that the pressure of the mains water supply to a building depends upon both the distance of the nearest water tower to the building and upon the head of water from the water tower to the building. The pressure of a water supply within a building may also vary. For example, a hotel may be provided with a water tank in the loft for supplying water to the individual rooms, in which case the pressure of the water supply to a particular room will depend on how many floors below the water tank the room is situated. Each hotel room is typically provided with a bathroom and a bathtub and, due to the variation of the pressure of the water supply, on different floors the taps used for filling the bathtub will have different maximum flow rates. Although bathtubs are conventionally provided with an overflow to convey excess water from the bathtub to a drain, for some bathtubs the flow rate of the water from the taps into the bathtub exceeds the rate at which the overflow can convey excess water to the drain. Thus there is a risk that if the taps should inadvertently be left on, or if a tap fails in the open position, then water will overflow the sides of the bath with consequential economic loss and structural damage. Accordingly there is a need to prevent such overflow.
An overflow control fitting for a bath is described in UK patent application GB 2263060. In GB 2263060, a capacitive level sensor is mounted at a level between the overflow outlet and the rim of a bathtub. A vertical tube allows water from the overflow outlet to reach the capacitive level sensor. A disadvantage of capacitive level sensors is that condensation of steam from the relatively warm water in a bathtub can cause false triggering of the sensor.
According to one aspect of the present invention there is provided a flow control system for a vessel comprising a liquid supply means and a drain, the flow control system comprising:
overflow means situated at a predetermined height in the vessel for drawing liquid from the vessel;
a flow rate sensor associated with the overflow means, the sensor being operable to provide an output when the flow rate through the overflow exceeds a predetermined flow rate; and
control means responsive to the sensor output for controlling the liquid supply to the vessel.
An advantage of such an apparatus is that it prevents a bathtub from inadvertently being overfilled. A further advantage of such an apparatus is that it allows a person to start filling their bathtub and then leave the apparatus to turn off the water supply to the bath without danger of overfilling the bathtub.
According to a second aspect of the invention, there is provided an overflow detector for use with a vessel having an overflow at a predetermined level for discharging liquid from the vessel comprising:
a conduit comprising an inlet for connection to the overflow, and an outlet; and
a sensor for providing an indicating signal when liquid flows through the overflow at a flow rate that exceeds a predetermined flow rate.
Other aspects of the invention provide an overflow system for a vessel, a combination of a vessel and an overflow detector, and a kit of parts for fitting to a vessel.
Preferred embodiments of the present invention will now be described by way of example only and with reference to the following drawings of which: